Requirements for the Resilience of Control Plane in GMPLS (draft-kim-ccamp-cpr-reqts-00.txt)

1. Requirements for the Resilience of Control Plane in GMPLS (draft-kim-ccamp-cpr-reqts-00.txt) CCAMP WG (59th IETF) Apr.04, 2004 Young Hwa Kim (yhwkim@etri.re.kr)

2. 1. Summary of the draft 2. Necessities for Resilience of Control Networks 3. Conclusion Contents

3. 1. Summary of the draft (2/1) • 3 components of CP : entities, nodes, and channels • Control networks • Control modes • Network configurations • Some concepts for the resilience of control networks • Control packet type • Active and standby control channels • Protection group … • Requirements for the resilience of control networks • Configuration of control networks • Priorities in control channels • Reverting and non-reverting modes of control channels

4. 1. Summary of the draft (2/2) • Necessities for the resilience of control networks • Relation to LMP • Possible functions for the resilience of control networks • Identification of an active control channel • Negotiation of switchover attributes • Verification of standby control channels • Automatic switchover • Forced switchover • Inquiry of switchover attributes • Notification of protocol errors • Parameter negotiation and Hello protocol

5. 2. Necessities for Resilience of Control Plane (1/3) • Current status of control plane • Weak concept of control network • Slow convergence of IP routing protocols due to hello intervals and expiration timer values • Alternative diverse paths between communication entities • A control network to experience an independent failure from the transport network, and its impact on connection setup and teardown requests • Also, control channels to share common physical routes with the transport network, and its impact on restoration of existing connections • Separation of control channels in GMPLS • Control channel management in LMP

6. 2. Necessities for Resilience of Control Plane (2/3) • Control channel management in LMP • Control channel activation with parameter negotiation • Hello protocol • Control channels independent of TE links • Possible multiple active control channels between a pair of nodes • If a failure on an active control channel occurs, alternative active control channels can be used, or the activation procedure can be performed. • No guarantee of the same level of service about TE links in a Degraded state

7. 2. Necessities for Resilience of Control Plane (3/3) • Is the status satisfactory? No. Then, why? • Few consideration of control modes and several control network configurations • While admitting the resilience of transport plane, no care of the resilience of control plane • No resilience concept in LMP • If there is no active control channel under the situation that a control channel is responsible for several TE links, the links fall into the Degraded state. We do not want it. • Even when there is a failure of an active control channel on restoration of existing connections, we do not want to start the control channel activation again, and we should be capable of identifying an alternative active control channel promptly.

8. 3. Conclusion • The draft introduced a framework for the resilience of control plane. • The control channel management in LMP is not sufficient for the resilience of control plane in GMPLS. • The resilience of transport plane may be included the current charter of the CCAMP WG, but whether the one of control plane is included in the WG or not … • If agreed to this point, let’s put the resilience of control plane into a basket of re-chartering items. • Then, I propose this draft as a WG document of the CCAMP WG. • Future works • Refinement of this draft; and • Proposal of a preliminary protocol specification.

9. Thank you. Young Hwa Kim (yhwkim@etri.re.kr)